1. Field of the Invention
The invention generally relates to filters and more particularly to fluid filters.
2. Description of the Background Art
A typical spin-on filter has a painted metal outer housing with a threaded nipple centered in the base of the filter. In operation, pressurized fluid flows into the filter through multiple radially spaced apertures at the base of the filter. The fluid then flows through the filter media and into a center tube, and is then circulated out of the filter through the threaded nipple and back to the engine or host connecting apparatus.
The prior art also includes filter designs with plastic housings, and at least one filter design with a transparent plastic housing. However, these filters are difficult to manufacture and have significant structural and reliability issues associated with the filter's crimped plastic-to-metal interface.